How do I delete the last whitespace after recursively printing Binary tree root

Question

the code itself is working though whenever I try to print the results which are integers of the following form: 1 2 3 4 5 I end up with an extra whitespace after the 5, how can I delete the last whitespace while keeping the integers separated on one line

public void inorder() {
        inrec(root);
    }
    private void inrec(BTNode<E> root) {
        
        if (root == null) {
            return;
        }
            inrec(root.getLeft());
            System.out.printf(root.getData()+" ");
            
            
            inrec(root.getRight());
        
    }

Answer 1

Try this.

public void inorder() {
    inrec(root, "", "");
}

private void inrec(Node<E> root, String prefix, String suffix) {
    if (root == null)
        return;
    System.out.print(prefix);
    inrec(root.getLeft(), "", " ");
    System.out.print(root.getData());
    inrec(root.getRight(), " ", "");
    System.out.print(suffix);
}

If you change inorder() to

public void inorder() {
    inrec(root, "(", ")");
}

It will print (1 2 3 4 5).